package tets;
import java.util.Scanner;
public class Test1 {
    public static void main(String[] args) {
        Scanner sc = new Scanner(System.in);
        int a = sc.nextInt();
        int b = sc.nextInt();
        int count=0;
        for (int i = a; i <=b; i++) {
           if(i%3==0 && i%5==0){
               count++;
           }

        }
        System.out.println(count);
    }
}

